1. Field of the Invention
The present invention relates to a tube joint for connecting, for example, a fluid tube for introducing or discharging a fluid.
2. Description of the Related Art
A tube joint has been hitherto used to connect a fluid tube to a fluid pressure-operated apparatus such as a cylinder. Such a tube joint has a body into which the fluid tube is inserted. The body is provided with a fastening pawl which protrudes by a predetermined length radially inwardly. When the fluid tube is slightly pulled in a direction opposite to the insertion direction after inserting the fluid tube, then the end of the fastening pawl bites into the outer circumferential surface of the fluid tube, and thus the fluid tube is prevented from disengagement from the body. The fastening pawl is retained by an engaging member attached to the body.
In the conventional tube joint as described above, for example, if it is intended to increase strength for preventing the fluid tube from disengagement from the body (referred to as pull-out strength), the biting amount of the fastening pawl into the outer circumferential surface of the fluid tube is excessively increased. As a result, the fluid tube may be cut off by the fastening pawl. On the other hand, if it is intended to limit the biting amount of the fastening pawl into the outer circumferential surface of the fluid tube, the pull-out strength is decreased, and the fluid tube may be disengaged from the body.